Atomising liquid fuel burners



Aug, 17, 1965 H. E. JACKSON ETAL 3,200,872

I ATOMISING LIQUID FUEL BURNERS Filed June 20, 1963 2 et heet 1 illlllllllllllllllllfl INVENTORS (IA HAROLD E. JA Ks 'DoumAs DEAN ATTORN EY:

1965 H. E. JACKSON ETAL 3,200,872

ATOMISING LIQUID FUEL BURNERS Filed June 20, 1963 2,- Sheets-Sheet 2 Iwvzwmas H.E. TAQKSON BY 3- R. DE'AH l k lbukhuim Wis AT-romuawgl United States Patent M 3,28%),872 ATGMISHNG LIQUH) FUEL BURNERS Harold Ernest Jackson, Piympton St. Mary, Devon, and Douglas Raymond Dean, ht. lludeaux, lymouth, Devon, England, assignors to 'llecalemit (Engineering) Limited, Plymouth, England, a British company Filed lune 20, 1%3, Ser. No. 289,371 Claims priority, application Great Britain, June 22, 1962, 24,130/62 9 Claims. (til. 158-76) This invention relates to atomising liquid fuel burners.

In one construction of such a burner, heated liquid fuel is fed to a chamber at the outlet end of a nozzle assembly and a stream of atomising fluid, for example air, fed through the nozzle assembly to the chamber, entrains and atomises the liquid fuel therein, ejecting the atomised fuel through the nozzle tip.

For any volume of flow of liquid fuel flow through the burner assembly, a particular rate of flow of the atomising fluid is required to achieve optimum atomisation of the liquid fuel. it is an object of this invention to provide an atomising device suitable for use as an atomising liquid fuel burner including means by which the volume of liquid fuel flow through the burner may be varied whilst automatically maintaining desired atomisation conditions.

According to the present invention an atomising device suitable for use as an atomising liquid fuel burner includes a body portion having respective liquid fuel and atomising fluid inlet passages, and a nozzle device including respective liquid fuel and atomising fluid conduits connected to the body portion, the inlet passages being connected to the nozzle conduits by respective fluid flow control valves adjustable by a common operating device.

The body portion may include also a further fluid flow control valve connected between the liquid fuel inlet passage and the liquid fuel flow control valve, and preferably also operable by the common operating device.

In a particular construction the inlet passages may be connected to the conduits of the nozzle device by respective passages containing flow control devices in the form of needle valves. The needles are connected together by a yoke and a shaft extends through the yoke, it being arranged that rotation of the shaft produces linear movement of the needles. Conveniently, the shaft may be operatively connected to, or be arranged to form, the further valve referred to above, rotation of the shaft then operating all three valves. Preferably, the needle valves are threaded to inserts in the yoke for individual adjustment relative to each other.

The liquid fuel inlet passage preferably is arranged to extend transversely through the body portion of the burner. This arrangement facilitates connection of the burners in a ring main fuel supply system and in use of the burner aids in maintaining the whole of the burner assembly at an elevated temperature thereby minimising chilling of liquid fuel during its passage through the burner assembly. Desirably, this fuel inlet passage is located close to the control valve asse. .bly in order to maintain this portion of the burner at a reasonably constant temperature so that viscosity changes in the liquid fuel, and hence variation in its rate of flow past the liquid fuel flow control valve, are minimised.

The nozzle device may be enclosed by a jacket containing a conduit, one end of which is connected to a cooling fluid inlet port in the body portion. The conduit is used to convey fluid, eg. water or air, to cool the tip of the nozzle device; the cooling fluid, elevated in temperature, then passes through the enclosing jacket to an outlet port provided in the body portion. This returning fluid aids also in preventing drop in tempera- 32%,872 Patented Aug. 17, 1965 ture of liquid fuel during its passage through the nozzle device.

By way of example, an embodiment of the invention will be described in greater detail with reference to the accompanying drawings, of which:

FIG. 1 shows a side view, mainly in elevation, of a burner assembly,

FIG. 2 is a section on the line A-A of FIG. 1, and

PEG. 3 is a section on the line BB of FIG. 1.

The burner assembly shown in the drawings comprises a body portion 1, which has a drilled base member 2 for mounting purposes, and a nozzle device 3 centered on the body portion 1 by dowels extending from the body portion and registering with drillings in the nozzle device 3. One such centering dowel 4, registering with a drilling 5 in the nozzle device, is shown in FIG. 1. A yoke 6 embraces the nozzle device 3 and is secured to either side of the body portion by bolts 7. A shaft 8 is threaded through the top of the yoke 6, rotation of the shaft 8 causing its bottom end to bear on the top of the nozzle device 3 and clamp it firmly in position on the body portion 1.

The nozzle device 3 has an outer tube 9 which encloses an oil supply conduit it within which is located an air supply conduit 11. At the outlet end. of the nozzle device 3, a tip member 12, having an outwardly flared aperture 13 and a throat portion extending into the nozzle device, is secured to the tube 9. A block 14, having drillings 15 and i6, is secured within the throat portion of the tip member 12 and a narrow annular atomising chamber 17 is defined around the flared aperture 15 between the tip member 112. and the block 14. The air supply conduit ll communicates with the charm ber 17 via the drilling 15, which is ali ed with the flared aperture 13, whilst the oil supply conduit it) communicates with the chamber 17 via the drilling 16. Oil is supplied through the conduit ill to a peripheral region of the chamber 17 and air fed through the conduit ll. to the central region of the chamber 17 entrains and atomises the oil therein ejecting the atomised oil through the flared orifice 13.

An oil supply passage 18 extends transversely through the base of the body portion 1. Leading from the passage 18 is a vertical drilling 19 which in turn is connected via cross-drillings to an oil metering chamber 20. The drilling 19 may be sealed off by a rotary plug valve 21 which is screw-threaded in the body portion 1. The oil metering chamber 2% communicates with a chamber 22 under control of a needle valve 23, slidable in the body portion 1. The chamber 22 communicates via drillings 2d, 25 with the oil supply conduit 10.

The base of the body portion has another transverse passage 26, which forms an air supply passage, connected by a vertical drilling 27 to an air metering chamber 23 which in turn communicates with a chamber 29 under control of a needle valve 30, slidable in the body portion 1. The chamber 29 communicates with the air supply conduit 11 via drillings 31, 32.

The plug valve 21 and the needle valves 23 and 3% have reduced shafts 33, 34, 35 respectively which. extend to the exterior of the body portion 1. The shafts 34 and 35 are screw-threaded to receive screw-threaded inserts 36, 37 of a yoke member 38 having a central aperture which is a sliding fit over the shaft 33 of the plug valve 21. side of the yoke member 38 abuts the shoulders at the bases of the shafts 33, 34, 35 whilst a collar 25% secured to the shaft 33 abuts the other side of the yoke member. The needle valves 23 and are individually adjustable with respect to the plug valve 21 by rotation of the threaded inserts 36, 37 and locking nuts 4d are provided to hold these valves in a desired position.

A cup-shaped head 41 encloses the shafts 33, 34,

One

e) and is secured fast to the shaft 33 by a grub-screw 42. Rotation of the head 41 causes opening or closing rotation of the plug valve 21 and corresponding non-rotary linear movement of the needle valves 23 and 30.

In use, the burner is connected to a ring main, which supplies heated oil, by means of the transverse passage 18, which thereby forms part of the said ring main, and to an air supply by means of the passage 26. Oil is fed to the oil supply conduit under control of the plug valve 21 and the needle valve 23 whilst air supply to the conduit 11 is controlled by the needle valve 30.

The valves 21, 23 and are so arranged that the valves 23 and 30 do not commence to open until the valve 21 has opened sutficiently to permit a free flow of oil from the supply passage 18 to the oil metering chamber 20. Further, the relative positions of the valves 23 and 39 are so adjusted that desired flow conditions of oil and air are obtained. By suitable design of the tips of the needle valves 23 and 30 it can be ensured that the relative proportions of oil and air flow, required for optimum atomisation, are maintained when these valves are opened further by rotation of the head 41.

In the burner assembly illustrated, the outer tube 9 contains a tube 43 which terminates at one end near the tip member 12 of the nozzle device 3. The other end of the tube 43 communicates via a drilling 44 with an inlet 45 in the base of the body portion 1. Cooling fluid, e.g. Water or air, fed to the inlet 45 is thus fed adjacent the tip member 12 and acts to cool the latter. The cooling fluid is thus raised in temperature and returns through the outer tube 9 of the nozzle assembly and a drilling 46, which extends through the body portion 1, to an outlet, not shown, provided in the base of the body portion on the opposite side to the inlet 45. The return flow of the cooling fluid through the outer tube 9 helps to maintain heated oil passing through the conduit 10 at an equable temperature.

It will be appreciated that the outer tube 9, together with the tube 43 and the associated components provided for the supply of cooling fluid, may be dispensed with if so desired.

In the burner assembly illustrated, the oil supply passage 18 is located immediately below the valve assembly and in use the whole of the burner assembly is raised to a high temperature thus minimising chilling of oil during its passage through the burner. Further, with this construction the temperature in the region of the valves is maintained at a reasonably constant level so that there are no marked changes of viscosity of the oil which would result in variation of flow across the needle valve 23.

The supply of oil to the burner from a ring main may be shut off by closing the plug valve 21 and the nozzle device 3 may then be removed for cleaning or replacement Without affecting the operation of any other burners connected in the ring main. Further, the assembly of Valves 21, 23 and 30 can easily be removed from the body portion 1, e.g. for cleaning purposes, without disturbing the relative settings of those valves.

We claim:

1. A liquid fuel atomising burner having a body portion, an elongated nozzle device projecting from said body portion, means releasably securing said nozzle device to said body portion, an atomising chamber at the distal end of said nozzle device, said nozzle device having first and second fluid flow conduits each communicating with said atomising chamber, a liquid fuel supply passage and an atomising fluid supply passage both extending completely through said body portion transversely of the direction of extent of said elongated nozzle device, first and second fluid flow passages in said body portion connecting said liquid fuel and atomising fluid supply passages respectively to said first and second fluid flow conduits, a first needle valve device for controlling liquid fuel flow from said liquid fuel supply passage through said first flow passage, a second needle valve ded vice for controlling atomising fluid flow from said atomising fluid supply passage through said second flow passage, a rotary stop valve member closable to isolate said first needle valve device from said liquid fuel supply passage, and a common operating means including a member rotatable to effect rotary opening movement of said rotary stop valve member with at least said first needle valve device initially closed and subsequent simultaneous non-rotary linear movement of said first and second needle valve devices whereby to elfect variation of liquid fuel and atomising fluid flows.

2. A liquid fuel atomising burner comprising a body portion, an elongated nozzle device projecting from the body portion, means securing the nozzle device to the body portion, an atomising chamber formed at the distal end of the nozzle device, first and second fluid flow conduits in the nozzle device and communicating with the atomising chamber, a liquid fuel inlet passage and an atomising fluid inlet passage in the body portion, respective fluid flow passages in the body portion connecting the liquid fuel inlet passage to the said first conduit and the atomising fluid inlet passage to the said second conduit, first and second needle valve means for controlling fluid flow along the respective passages in the body portion, rotary valve means for controlling liquid fuel flow between the liquid fuel inlet passage and the first needle valve means, a rotatable operating shaft for the rotary valve means, a yoke member carried by the shaft whereby rotation of the shaft produces linear movement of the yoke member, the first and second needle valve means each having a needle valve member connected to the yoke member to permit adjustment of the needle valve members relative to one another, means for rotating the said operating shaft thereby first to open the said rotary valve means with the first and second needle valve means closed and subsequently to open both the first and second needle valve means whereby to obtain a desired relationship between liquid fuel and atomising fluid flow rates for varying liquid fuel flow rates, a coolant jacket surrounding the nozzle device, and fluid flow passages within the jacket for circulation of coolant liquid adjacent the atomising chamber.

3. An atomising burner according to claim 2 in which the atomising chamber is a narrow annular chamber extending transversely of the direction of extent of the nozzle device, and in which said first flow conduit communicates with a perhipheral portion of said annular chamber and said second flow conduit communicates with the central aperture of said annular chamber, whereby liquid fuel supplied to said annular chamber is entrained and atomised by atomising fluid emergent from said second conduit.

4. A liquid fuel atomising burner comprising a body portion and an elongated nozzle device forming separate unitary assemblies, means releasably clamping said nozzle device to and in engaging relationship with said body portion whereby said nozzle device projects from said body portion, an atomising chamber formed at the distal end of said nozzle device, first and second flow conduits in said nozzle device each communicating with said atomising chamber, a liquid fuel supply passage and an atomising fluid supply passage formed in and extending completely through said body portion transversely to the direction of extent of said nozzle device, said body portion further including first and second flow passages connecting said liquid fuel supply passage and said atomising fluid supply passage with said first and second flow conduits respectively, first and second needle valve devices disposed in the body portion for controlling fluid flow along said first and second flow passages in the body portion, at least said first needle valve device being located closely adjacent said liquid fuel supply passage, means linking together said first and second needle valve devices for simultaneous non-rotary linear movement thereof, and a common operating member for effecting said linear movement of the gfirst and second needle valve devices whereby to adjust the values of the liquid fuel and atomising fluid flows.

5". A liquid fuel atomising burner as claimed in claim 4%, and including a stop valve member for isolating said first needle valve device from said liquid fuel supply passage, said means linking together said first and sec ond needle valve devices further linking them with said stop valve member, said first and second needle valve devices and said stop valve member extending in spaced parallel relation with each other, and said common operating member being a rotary member operable to move said linking means to effect linear non-rotary movement of said first and second needle valve devices and linear movement of said stop member whereby rotation of said operating member in one sense can open said stop valve member with at least the first needle valve initially closed and subsequently during continued opening movement of said stop valve member effect simultaneous opening movement of said first and second needle valve devices.

6. A liquid fuel atomising burner comprising a body portion and an elongated nozzle device forming separate unitary assern lies, said nozzle device having inlet and outlet ends, an atomising chamber formed adjacent said outlet end, said nozzle device having first and second fluid flow conduits each communicating with said atomising chamber, said body portion having first and second fluid flow passages, a liquid fuel supply passage formed in said portion and communicating with said first flow passage, an atomising fluid supply passage formed in said body portion and communicating with said second flow passage, means releasably clamping said nozzle device at the inlet end thereof to and in engagement with said body portion with said first and second flow conduits in fluid communication With said first and second flow passages respectively, said body portion also including first and second needle valve devices for controlling fluid flow along said first and second flow passages respectively and a stop valve member closable to isolate said first needle valve device from said liquid fuel supply passage, means linking together said first and second needle valve devices and said stop valve member for simultaneous non-rotary linear movement of said needle valve devices and linear movement of said stop valve member, and a common operating member for said needle valve devices and said stop valve member for opening said stop member With at least said first needle valve initially closed and subsequently to open both said first and second needle valve devices whereby to adjust the values of liquid fuel and atomising fluid flows.

7. Apparatus as claimed in claim 6, and in Which said nozzle device at said outlet end thereof comprises an inner member surrounded by an outer member, said inner and outer members defining between them a narrow annular space extending transversely of said elongated nozzle assembly and forming said atomising chamber, said outer member defining a flared outlet orifice communicating With the centre region of said atomising chamber, said inner member having a central aperture by which said second flow conduit communicates With said atomising chamber and further providing said communication between said first flow conduit and the said atomising chamber in a peripheral region thereof.

8. A liquid fuel atomising burner comprising a body portion forming a unitary assembly, and an elongated nozzle tube assembly forming a separate unitary assembly, said body portion having a liquid fuel supply passage and an atomising fluid supply passage, first and second fluid fioW passages defined within said body portion and communicating with said liquid fuel and atomising fluid supply passages respectively, said body portion including first and second needle valve devices for controlling fluid flow along said first and second flow passages respectively and a rotary stop valve member closable to isolate said first needle valve device from said liquid fuel supply passage, said nozzle tube assembly having an inlet end and an outlet end, a flared outlet orifice formed at the said outlet end of the nozzle tube assembly, an atomising chamber formed adjacent the outlet end of said nozzle tube assembly and communicating With said outlet orifice, said nozzle tube assembly also including first and second fluid flow conduits each communicating with said atomising chamber, means releasably clamping said nozzle tube assembly at the inlet end thereof in operable engage ment with said body portion and with said first and second flow conduits in fluid communication with said first and second flow passages respectively for delivery of liquid fuel and atomising fluid to said atomising chamber under control of said first and second needle valve devices, said liquid fuel and atomising fluid supply passages extending completely through said body portion transversely of the direction of extent of said elongated nozzle tube assembly and at least said first needle valve device and said rotary stop valve member being located closely adjacent said liquid fuel supply conduit, said first and second needle valve devices extending in parallel spaced relationship With each other, a cross-member linking together said first and second needle valve devices, an operating shaft extending through said cross-member between said first and second needle valve devices and threadedly mounted in said body portion whereby rotation of said shaft elfects rotary and linear movement thereof and non-rotary linear movement of said first and second needle valve devices, one end of said shaft being adapted to form said rotary stop valve member and an operating member secured to the other end of said shaft whereby rotation of said shaft firstly opens said stop valve member With at least the first needle valve closed and subsequently opens both said first and second needle valve devices to adjust the values of the liquid fuel and atomising fluid flows.

9. A liquid fuel burner as claimed in claim 8, and in Which said nozzle tube assembly further includes an outer tube surrounding said first and second flow conduits, means closing said outer tube at said outlet end and the end adjacent the body portion of the nozzle tube assembly, and a further fiow conduit extending along said nozzle tube assembly Within said outer tube and terminating short of said outlet end of the nozzle tube assembly, said outer tube and said further flow conduit defining coolant fluid flow paths for circulating coolant fluid to the region of said outlet orifice and said atomising chamber, and returning said coolant fluid in contact With said first and second flow conduits to coolant outlet means.

References (Iited by the Examiner UNITED STATES PATENTS Re. 16,307 3/26 McCutcheon 158-27.4 1,551,651 9/25 Everhart 158-120 1,581,725 4/26 Egersdorfer 15876 1,953,853 4/34 Gregor 15873 2,192,193 3/40 Johnson 137630.19

FOREIGN PATENTS 834,176 8/38 France.

1,061,303 7/59 Germany.

FREDERICK L. MATTESON, 1a., Primary Examiner.

MEYER PERLIN, JAMES W. WESTHAVER,

Examiners. 

1. A LIQUID FUEL ATOMISING BURNER HAVING A BODY PORTION, AN ELONGATED NOZZLE DEVICE PROJECTING FROM SAID BODY PORTION, MEANS RELEASABLE SECURING SAID NOZZLE DEVICE TO SAID BODY PORTION, AN ATOMISING CHAMBER AT THE DISTAL END OF SAID NOZZLE DEVICE, SAID NOZZLE DEVICE HAVING FIRST AND SECOND FLUID FLOW CONFUITS EACH COMMUNICATING WITH SAID ATOSMISING CHAMBER, A LIQUID FUEL SUPPLY PASSAGE AND AN ATOMISING FLUID SUPPLY PASSAGE BOTH EXTENDING COMPLETELY THROUGH SAID BODY PORTION TRANSVERSELY OF THE DIRECTION OF EXTENT OF SAID ELONGATED NOZZLE DEVICE, FIRST AND SECOND FLUID FLOW PASSAGES IN SAID BODY PORTION CONNECTING SAID LIQUID FUEL AND ATOMISING FLUID SUPPLY PASSAGES RESPECTIVELY TO SAID FIRST AND SECOND FLUID FLOW CONDUITS, A FIRST NEEDLE VALVE DEVICE FOR CONTROLLING LIQUID FUEL FLOW FROM SAID LIQUID FUEL SUPPLY PASSAGE THROUGH SAID FIRST FLOW PASSAGE, A SECOND NEEDLE VALVE DEVICE FOR CONTROLLING ATOMISING FLUID FLOW FROM SAID ATOMISING FLUID SUPPLY PASSAGE THROUGH SAID SECOND FLOW PASSAGE, A ROTARY STOP VALVE MEMBER COLSABLE TO ISOLATE SAID FIRST NEEDLE VALVE DEVICE FROM SAID LIQUID FUEL SUPPLY PASSAGE, AND A COMMON OPERATING MEANS INCLUDING A MEMBER ROTATABE TO EFFECT ROTARY OPENING MOVEMENT OF SAID ROTARY STOP VALVE MEMBER WITH AT LEAST SAID FIRST NEEDLE VALVE DEVICE INITIALLY CLOSED AND SUBSEQUENT SIMULTANEOUS NON-ROTARY LINEAR MOVEMENT OF SAID FIRST AND SECOND NEEDLE VALVE DEVICES WHEREBY TO EFFECT VARIATION OF LIQUID FUEL AND ATOMISING FLUID FLOWS. 